Unconventional Near‐Equilibrium Nucleation of Graphene on Si‐Terminated SiC(0001) Surface

Abstract The transfer‐free character of graphene growth on Silicon Carbide (SiC) makes it compatible with state‐of‐the‐art Si semiconductor technologies for directly fabricating high‐end electronics. Although significant progress has been achieved in epitaxial growth of graphene on SiC recently, the underlying nucleation mechanism remains elusive. Here, we present a theoretical study to elucidate graphene near‐equilibrium nucleation on Si‐terminated hexagonal‐SiC(0001) surface. It is found that the ultra‐large lattice mismatch between SiC(0001) surface and graphene and the highly localized electron distribution on SiC(0001) surface lead to a distinctive nucleation process: (i) Most of the magic carbon clusters on SiC(0001) show only C 1 symmetry and are mainly composed of pentagonal rings; (ii) Two possible nucleation pathways are revealed, i.e ., longitudinal and circular modes; (iii) Carbon clusters are more stable on flat terraces than near atomic step edges. Based on above findings, a graphene nucleation diagram on SiC(0001) is established and experimentally observed contradictories for graphene growth on SiC(0001) are answered. Our in‐depth understanding on graphene nucleation on SiC(0001) extends nucleation mechanisms of 2D crystals and will benefit high‐quality graphene growth on SiC(0001).